Accumulator injection systems which operate with very high injection pressures are increasingly being used as fuel supply systems for internal combustion engines. In these accumulator injection systems, fuel is delivered by means of a high-pressure pump into a fuel injector, from which the fuel is injected into the combustion chamber of the internal combustion engine. A fuel injector of this type has an injection valve which is hydraulically opened or closed by a control valve with the help of applied fuel pressure. This control valve is actuated by an actuator.
Because of the high pressure, there is a greater backflow of fuel from the fuel injector particularly during the control process by the control valve. This backflow is carried back into a fuel reservoir via a leakage line. As known, for example from DE 199 40 387 C1, the leakage connection is formed on the injector by a stepped bore into which a line with a connection nipple is inserted. To prevent the connection nipple from being pushed out by fuel draining away out of the leakage connection, the connection nipple is secured to the fuel injector by means of an axial securing device. This arrangement, however, is relatively expensive and incorporates a great many individual components.
An alternative option for fixing a leakage line with nipple to a leakage connection of the injector by means of a spring element is known, for example, from EP 0 886 065 A1. This solution, however, likewise has a great many components and entails relatively high production and installation costs.